I will add to what Ralph said that the most likely place for "signal
loss"
will be at the connection(s) you make at each end of whatever coax you
use.
Buy some good quality pre assembled coax if at all possible. Avoid Radio
Shack junk.

That remimded me of some pix I saw of a cut away of a RS connector , maybe
it was L type where a spring or coil of wire was used. That thing acted
almost like a RF choke and had a very high loss.